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CastCheck methodology v0.2 · data through 2026-08-30

Trenton Mercer · ECMWF IFS HRES · lead day 3

KTTN · ifs_hres · lead 3

Target day = initialization date + 3 days. This page is a permanent link: the numbers change as history accumulates, the address and the methodology version do not.

Scores use the latest model version segment, ifs-gpid161, starting 2026-08-01 — days before that ran a different version of the model and are excluded rather than silently pooled. Of the scored days, 1 carry a QC flag on the observation.

JSON for this page CSV of the daily errors Cite this page

Every number for this combination

All four windows × both initializations × both interpolations × both variables. Errors are computed in °C and shown in °F; CI is a 95 % moving-block bootstrap interval. MAE debiased and skill, debiased remove the constant offset of the window first, so a station that the model always reads a degree too warm is not scored as if it had no skill — compare the two skill columns to see how much of the error is a fixed offset. n QC next to n counts days whose observation carries a QC flag.

VariableInitMethod Windown MAE °F MAE debiased Bias °F RMSE °F ±1 °F±2 °F±3 °F Skill Skill, debiased Period
tmax00Zbilinear30d22 1 QC2.35 [1.74, 2.98]2.40-0.18 [-1.26, 0.98]3.08 [2.09, 3.91]32% [12%, 44%]50%73%+0.25+0.162026-08-04 → 2026-08-30
tmax00Zbilinear90d22 1 QC2.35 [1.65, 3.07]2.40-0.18 [-1.50, 0.95]3.08 [1.92, 3.97]32% [0%, 44%]50%73%+0.25+0.162026-08-04 → 2026-08-30
tmax00Zbilinear365d22 1 QC2.35 [1.55, 3.12]2.40-0.18 [-1.61, 1.16]3.08 [1.77, 4.08]32% [0%, 45%]50%73%+0.25+0.162026-08-04 → 2026-08-30
tmax00Zbilinearall22 1 QC2.35 [1.61, 3.05]2.40-0.18 [-1.68, 1.08]3.08 [1.80, 4.05]32% [0%, 44%]50%73%+0.25+0.162026-08-04 → 2026-08-30
tmax00Znearest30d22 1 QC2.49 [1.90, 3.06]2.52-0.11 [-1.36, 1.30]3.19 [2.27, 3.96]36% [18%, 50%]50%68%+0.21+0.122026-08-04 → 2026-08-30
tmax00Znearest90d22 1 QC2.49 [1.74, 3.13]2.52-0.11 [-1.53, 1.27]3.19 [2.02, 4.01]36% [9%, 52%]50%68%+0.21+0.122026-08-04 → 2026-08-30
tmax00Znearest365d22 1 QC2.49 [1.63, 3.14]2.52-0.11 [-1.55, 1.47]3.19 [1.97, 4.11]36% [7%, 53%]50%68%+0.21+0.122026-08-04 → 2026-08-30
tmax00Znearestall22 1 QC2.49 [1.71, 3.12]2.52-0.11 [-1.70, 1.42]3.19 [1.99, 4.08]36% [6%, 52%]50%68%+0.21+0.122026-08-04 → 2026-08-30
tmax12Zbilinear30d22 1 QC2.75 [2.04, 3.48]2.72-0.58 [-1.80, 0.53]3.58 [2.56, 4.44]32% [18%, 44%]50%59%+0.12+0.052026-08-04 → 2026-08-30
tmax12Zbilinear90d22 1 QC2.75 [2.01, 3.58]2.72-0.58 [-2.01, 0.78]3.58 [2.51, 4.52]32% [16%, 44%]50%59%+0.12+0.052026-08-04 → 2026-08-30
tmax12Zbilinear365d22 1 QC2.75 [2.02, 3.64]2.72-0.58 [-2.35, 0.91]3.58 [2.51, 4.54]32% [12%, 43%]50%59%+0.12+0.052026-08-04 → 2026-08-30
tmax12Zbilinearall22 1 QC2.75 [2.03, 3.60]2.72-0.58 [-2.08, 0.72]3.58 [2.51, 4.45]32% [10%, 44%]50%59%+0.12+0.052026-08-04 → 2026-08-30
tmax12Znearest30d22 1 QC2.88 [2.19, 3.60]2.86-0.55 [-1.78, 0.63]3.70 [2.66, 4.54]23% [7%, 38%]50%64%+0.08+0.002026-08-04 → 2026-08-30
tmax12Znearest90d22 1 QC2.88 [2.12, 3.66]2.86-0.55 [-1.94, 0.77]3.70 [2.58, 4.60]23% [0%, 41%]50%64%+0.08+0.002026-08-04 → 2026-08-30
tmax12Znearest365d22 1 QC2.88 [2.12, 3.69]2.86-0.55 [-2.18, 1.03]3.70 [2.54, 4.63]23% [0%, 40%]50%64%+0.08+0.002026-08-04 → 2026-08-30
tmax12Znearestall22 1 QC2.88 [2.14, 3.66]2.86-0.55 [-2.02, 0.83]3.70 [2.48, 4.54]23% [0%, 40%]50%64%+0.08+0.002026-08-04 → 2026-08-30
tmin00Zbilinear30d22 1 QC4.89 [4.26, 6.27]2.28+4.89 [4.26, 6.27]5.53 [4.85, 6.82]5% [0%, 12%]9%36%-0.27+0.362026-08-04 → 2026-08-30
tmin00Zbilinear90d22 1 QC4.89 [4.33, 6.94]2.28+4.89 [4.33, 6.94]5.53 [4.96, 7.30]5% [0%, 12%]9%36%-0.27+0.362026-08-04 → 2026-08-30
tmin00Zbilinear365d22 1 QC4.89 [4.26, 6.91]2.28+4.89 [4.26, 6.91]5.53 [4.85, 7.39]5% [0%, 13%]9%36%-0.27+0.362026-08-04 → 2026-08-30
tmin00Zbilinearall22 1 QC4.89 [4.28, 7.73]2.28+4.89 [4.28, 7.73]5.53 [4.88, 7.87]5% [0%, 12%]9%36%-0.27+0.362026-08-04 → 2026-08-30
tmin00Znearest30d22 1 QC5.21 [4.58, 6.54]2.24+5.21 [4.58, 6.54]5.79 [5.09, 7.11]5% [0%, 12%]9%32%-0.35+0.372026-08-04 → 2026-08-30
tmin00Znearest90d22 1 QC5.21 [4.66, 7.28]2.24+5.21 [4.66, 7.28]5.79 [5.20, 7.56]5% [0%, 12%]9%32%-0.35+0.372026-08-04 → 2026-08-30
tmin00Znearest365d22 1 QC5.21 [4.58, 7.18]2.24+5.21 [4.58, 7.18]5.79 [5.09, 7.71]5% [0%, 13%]9%32%-0.35+0.372026-08-04 → 2026-08-30
tmin00Znearestall22 1 QC5.21 [4.62, 8.08]2.24+5.21 [4.62, 8.08]5.79 [5.14, 8.19]5% [0%, 12%]9%32%-0.35+0.372026-08-04 → 2026-08-30
tmin12Zbilinear30d22 1 QC4.09 [3.09, 5.05]2.08+4.09 [3.09, 5.05]4.78 [3.72, 5.69]5% [0%, 12%]23%41%-0.06+0.412026-08-04 → 2026-08-30
tmin12Zbilinear90d22 1 QC4.09 [2.96, 5.31]2.08+4.09 [2.96, 5.31]4.78 [3.54, 5.97]5% [0%, 12%]23%41%-0.06+0.412026-08-04 → 2026-08-30
tmin12Zbilinear365d22 1 QC4.09 [2.95, 5.33]2.08+4.09 [2.95, 5.33]4.78 [3.40, 6.02]5% [0%, 13%]23%41%-0.06+0.412026-08-04 → 2026-08-30
tmin12Zbilinearall22 1 QC4.09 [2.96, 5.37]2.08+4.09 [2.96, 5.37]4.78 [3.49, 6.01]5% [0%, 12%]23%41%-0.06+0.412026-08-04 → 2026-08-30
tmin12Znearest30d22 1 QC4.44 [3.52, 5.38]2.01+4.44 [3.52, 5.38]5.07 [4.06, 5.97]5% [0%, 12%]18%36%-0.15+0.432026-08-04 → 2026-08-30
tmin12Znearest90d22 1 QC4.44 [3.43, 5.61]2.01+4.44 [3.43, 5.61]5.07 [3.90, 6.24]5% [0%, 12%]18%36%-0.15+0.432026-08-04 → 2026-08-30
tmin12Znearest365d22 1 QC4.44 [3.40, 5.65]2.01+4.44 [3.40, 5.65]5.07 [3.81, 6.27]5% [0%, 13%]18%36%-0.15+0.432026-08-04 → 2026-08-30
tmin12Znearestall22 1 QC4.44 [3.43, 5.73]2.01+4.44 [3.43, 5.73]5.07 [3.90, 6.31]5% [0%, 12%]18%36%-0.15+0.432026-08-04 → 2026-08-30

+ model too warm · − model too cold · bias interval includes zero · ★ lowest MAE · = not distinguishable from the leader · ▼ significantly worse · n < 30 greyed and unranked · CI is a 95 % moving-block bootstrap interval.

Daily error, last 90 days

Daily forecast minus observed error in °F for ECMWF IFS HRES at KTTN, lead day 3, 00Z bilinear tmax+10+50-5-102026-08-04: -3.01 °F2026-08-10: +2.08 °F2026-08-11: -3.97 °F2026-08-12: +2.74 °F2026-08-13: +4.13 °F2026-08-14: -0.86 °F2026-08-15: +2.78 °F2026-08-16: +0.4 °F2026-08-17: +0.16 °F2026-08-18: +3.27 °F2026-08-19: +1.35 °F2026-08-20: -7.95 °F2026-08-21: +2.24 °F2026-08-22: -6.99 °F2026-08-23: +0.56 °F2026-08-24: +0.17 °F2026-08-25: +0.81 °F2026-08-26: -1.8 °F2026-08-27: -2.62 °F2026-08-28: -0.67 °F2026-08-29: +1.91 °F2026-08-30: +1.26 °F2026-08-042026-08-30°F, forecast − observed
Forecast − observed, °F, 00Z bilinear daily maximum. The dashed line is zero; the thick line is a centred 7-day mean, drawn only where the whole window is present. Gaps are days with no score, never interpolation. Hover a point for its date and value.
The same series as a table (27 days, newest first) · download CSV
Climatological dayError °F
2026-08-30+1.26
2026-08-29+1.91
2026-08-28-0.67
2026-08-27-2.62
2026-08-26-1.80
2026-08-25+0.81
2026-08-24+0.17
2026-08-23+0.56
2026-08-22-6.99
2026-08-21+2.24
2026-08-20-7.95
2026-08-19+1.35
2026-08-18+3.27
2026-08-17+0.16
2026-08-16+0.40
2026-08-15+2.78
2026-08-14-0.86
2026-08-13+4.13
2026-08-12+2.74
2026-08-11-3.97
2026-08-10+2.08
2026-08-09—
2026-08-08—
2026-08-07—
2026-08-06—
2026-08-05—
2026-08-04-3.01

Error distribution

Distribution of the signed daily error in °F for ECMWF IFS HRES at KTTN, lead day 3-10 to -9 °F: 0 days-9 to -8 °F: 0 days-8 to -7 °F: 1 day-7 to -6 °F: 1 day-6 to -5 °F: 0 days-5 to -4 °F: 0 days-4 to -3 °F: 2 days-3 to -2 °F: 1 day-2 to -1 °F: 1 day-1 to 0 °F: 2 days0 to 1 °F: 5 days1 to 2 °F: 3 days2 to 3 °F: 4 days3 to 4 °F: 1 day4 to 5 °F: 1 day5 to 6 °F: 0 days6 to 7 °F: 0 days7 to 8 °F: 0 days8 to 9 °F: 0 days9 to 10 °F: 0 daysdashed: P50 |e| 2 · P90 |e| 4.11 °F-100+10 °Fn = 22 days
All scored days for 00Z bilinear daily maximum, 20 equal bins. The dashed marks are the 50th and 90th percentiles of the absolute error, mirrored on both sides. Hover a bar for its bin and count.
Bin counts as a table
From °FTo °FDays
-10.00-9.000
-9.00-8.000
-8.00-7.001
-7.00-6.001
-6.00-5.000
-5.00-4.000
-4.00-3.002
-3.00-2.001
-2.00-1.001
-1.00+0.002
+0.00+1.005
+1.00+2.003
+2.00+3.004
+3.00+4.001
+4.00+5.001
+5.00+6.000
+6.00+7.000
+7.00+8.000
+8.00+9.000
+9.00+10.000

Month by month

00Z bilinear daily maximum, newest first.

Monthn MAE °FBias °F
2026-08222.35 -0.18

Availability

ModelScored period DaysCoverage
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22
ECMWF IFS HRES2026-08-04 → 2026-08-30 22

Compared with other models

Paired bootstrap on the days both models cover (90d, 00Z, bilinear, daily maximum). Negative means ECMWF IFS HRES has the lower MAE. "Distinguishable" means the 95 % interval excludes zero.

Other modelCommon days MAE difference °FDistinguishable
ECMWF AIFS Single 22 +0.84 [-0.32, 1.91] no
NCEP GFS 22 -0.25 [-0.93, 0.30] no
GraphCast (IFS init) 20 +0.47 [-0.79, 1.41] no
Persistence (baseline) 22 -0.78 [-1.49, -0.19] yes

Cite this page

ShortCastCheck, KTTN ifs_hres lead 3, methodology v0.2, accessed 2026-08-31, https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/3/

LongCastCheck (2026). Station-level verification of raw weather-model 2 m temperature forecasts: KTTN (Trenton Mercer), model ifs_hres, lead day 3. Methodology version 0.2, schema version 0.1, data through 2026-08-30. Accessed 2026-08-31. https://castcheck.zifanzhang.com/station/KTTN/model/ifs_hres/lead/3/

Accessed2026-08-31 (data through 2026-08-30; page built 2026-08-31T03:52:06+00:00)

JSON CSV all scores methodology v0.2 licence